1. Field of the Invention
The present invention relates to thermal transfer material, and a printing method and printer used with the same. More particularly, the present invention relates to thermal transfer material suitable for printing to an image receiving material of which a printing surface is not very smooth, and a printing method and printer used with the same.
2. Description Related to the Prior Art
Material with a not smooth surface, such as paper or fabric, has a characteristic that it is difficult for the surface to receive ink stably. It happens that dots are missing or out of order. Images are very hard to be recorded with high quality. There is a known system in which the image is created once on an intermediate material, and then is transferred to an image receiving material. JP-A 05-000575 discloses transfer material, which includes a support with releasability, and a layer of developer agent overlaid on the support.
In the printer according to this prior document, photosensitive pressure-sensitive material of a continuous sheet, while fed, is exposed by light reflected by an original. In the photosensitive pressure-sensitive material, a photosensitive pressure-sensitive layer includes a great number of micro capsules distributed uniformly. Each of the micro capsules contains dye precursor, photo-setting resin and photo polymerization initiator. The photo-setting resin is hardened in response to application of exposure light. A certain number of micro capsules in the photosensitive pressure-sensitive material are hardened, the certain number being proportional to an amount of the exposure light. Then the photosensitive pressure-sensitive material is placed on the transfer material, and passed together between press rollers. Then the remainder of the micro capsules without being hardened even after the exposure are destroyed. The dye precursor flows from the micro capsules, and reacts upon the developer agent in a developer layer, so that a full-color image is created in the developer layer of the transfer material.
The image of the original is read by a scanner. A computer is operated to detect a colored portion in the image. Then a thermal printer is used to produce a printing plate of a screen sheet according to the colored portion of the image as detected by the computer, the screen sheet consisting of mesh sheet of nylon or the like and thermosensitive resin overlaid on the mesh sheet. To be precise, the thermosensitive resin is melted in positions corresponding to the colored portion of the image of the original. Only portions of the mesh sheet remain those positions.
After this, the screen sheet is placed on the transfer material by positioning the image in the transfer material suitably. Then polyolefin resin dispersion liquid is pressed and applied as a thermoplastic resin coating to the transfer material. When the screen sheet is separated and dried. The thermoplastic resin is kept with the transfer material to cover the image.
The thermoplastic resin of the transfer material is placed on an image receiving sheet material of polyethylene terephthalate film, and is passed together between hot press rollers, to be attached thereto. Then the transfer material is fused to the image receiving material by means of the thermoplastic resin. After cooling down to the room temperature, the support in the transfer material is peeled. The portion of the transfer material with the image is transferred to the image receiving material.
The above-mentioned printer only forms the image in the developer layer of the transfer material. For transferring the developer layer to the image receiving material with the image, the additional steps are required, the steps including the step of providing the image of the transfer material with the thermoplastic resin, the step of fusing the transfer material to the image receiving material by means of the thermoplastic resin, and the step of peeling the support of the transfer material. Thus, the printer has a shortcoming in the complexity in the printing process and necessity of much time for printing.
In view of the foregoing problems, an object of the present invention is to provide thermal transfer material and a printing method and printer usable with the same, with which easy and rapid printing is possible with an image receiving material of which a printing surface is not very smooth.
In order to achieve the above and other objects and advantages of this invention, a thermal transfer material comprises a support. A release layer is overlaid on the support. A transfer layer is overlaid on the release layer, has thermoplasticity, and is adapted to forming an image therein.
The transfer layer includes thermoplastic resin, and placed on image receiving material. The thermoplastic resin is melted by being heated, and transfers the transfer layer to the image receiving material by being pressurized.
At least one of the release layer and the transfer layer is transparent.
In a preferred embodiment, a thermal transfer material comprises a support. A release layer is overlaid on the support. A coloring transfer layer is overlaid on the release layer, has thermoplasticity, and is colorable by being exposed and pressurized.
The coloring transfer layer further includes dye precursor and photo-setting resin, the dye precursor is colorable in a predetermined color, and the photo-setting resin is hardened in response to light of a color complementary to the predetermined color.
The coloring transfer layer includes developer agent and plural micro capsules distributed uniformly. The micro capsules include the dye precursor and the photo-setting resin, and the dye precursor flows out by pressurization, and reacts upon the developer agent to develop color.
The predetermined color comprises at least three colors, the dye precursor comprises at least three types, the photo-setting resin comprises at least three types, and light of at least three complementary colors is applied to the photo-setting resin, for coloring in a full-color manner.
In another preferred embodiment, the support has a continuous shape. The predetermined color comprises at least first, second and third colors. At least first, second and third regions are arranged cyclically in a material longitudinal direction, colorable in the first, second and third colors, and adapted to image recording in sequence for full-color recording.
According to one aspect of the invention, a thermal transfer material comprises a support. A release layer is overlaid on the support. An ink receiving transfer layer is overlaid on the release layer, and has thermoplasticity and ink receptivity.
The ink receiving transfer layer includes porous ink receiving substance.
According to another aspect of the invention, a thermal transfer material comprises a support. A release layer is overlaid on the support. A thermosensitive coloring transfer layer is overlaid on the release layer, is colorable in a predetermined color in response to application of heat, and has thermoplasticity.
The coloring transfer layer includes first coloring substance and plural micro capsules distributed uniformly. The micro capsules include second coloring substance, and the second coloring substance thermally reacts upon the first coloring substance to develop the predetermined color.
Furthermore, a heat resistant layer is overlaid on the support in a surface thereof opposite to the release layer. At least one of the support, the release layer and the heat resistant layer is transparent.
The support has a continuous shape. The predetermined color comprises at least first, second and third colors. At least first, second and third regions are arranged cyclically in a material longitudinal direction, colorable in the first, second and third colors, and adapted to image recording in sequence for full-color recording.
In a further preferred embodiment, the predetermined color comprises at least first, second and third colors. The coloring transfer layer is constituted by a combination of at least first, second and third thermosensitive coloring layers, overlaid on one another in sequence from the release layer, colorable in the first, second and third colors, and adapted to image recording in sequence for full-color recording. The first and second coloring layers are disposed closer to the support, and have optical fixability in response to electromagnetic rays in a predetermined wavelength range. The third coloring layer is disposed farthest from the support, and includes the thermoplastic resin, and the thermoplastic resin is heated to a glass transition point thereof by application of heat for coloring.
According to a further aspect of the invention, a printing method in which thermal transfer material is used is provided. The thermal transfer material comprises a support. A release layer is overlaid on the support. A transfer layer is overlaid on the release layer, and has thermoplasticity. In the printing method, an image is formed in the transfer layer. The transfer layer is placed on image receiving material after the image is formed. The thermal transfer material is heated and pressurized while the transfer layer is placed on, so as to transfer the transfer layer to the image receiving material.
The transfer layer is a coloring transfer layer colorable by being exposed and pressurized. The image forming step includes exposing the coloring transfer layer. The heating and pressurizing step includes coloring the image formed by exposure.
The coloring transfer layer further includes thermoplastic resin, dye precursor and photo-setting resin, the dye precursor is colorable in a predetermined color, and the photo-setting resin is hardened in response to light of a color complementary to the predetermined color. The image forming step includes exposing the thermal transfer material by light of the complementary color according to image data of the predetermined color, for hardening part of the photo-setting resin associated with the image data, to disable part of the dye precursor from developing color. The heating and pressurizing step includes destroying part of the photo-setting resin remaining unhardened, for causing the dye precursor to develop color.
According to another aspect of the invention, a printing method in which thermal transfer material is used is provided. The thermal transfer material comprises a support. A release layer is overlaid on the support. A thermosensitive coloring transfer layer is overlaid on the release layer, is colorable in a predetermined color in response to application of heat, and has thermoplasticity. In the printing method, the coloring transfer layer is placed on image receiving material. The thermal transfer material is heated and pressurized while the coloring transfer layer is placed on, so as to record an image thermally in the coloring transfer layer and transfer the coloring transfer layer to the image receiving material.
The coloring transfer layer comprises first, second and third thermosensitive coloring transfer layers, the first, second and third regions have respectively the first, second and third coloring transfer layers, and the first and second coloring transfer layers have optical fixability in response to electromagnetic rays in a predetermined wavelength range. Furthermore, image recording is effected to the first and second coloring transfer layers by heating and pressurization. The first and second coloring transfer layers are optically fixed after the image recording. The first and second coloring transfer layers are transferred to image receiving material by heating and pressurization after fixation. The heating and pressurizing step includes image recording and transfer of the third coloring transfer layer.